How to create a FreeBSD 8.0 boot CD without boot.flp?

Pierre-Luc Drouin pldrouin at
Wed Feb 10 21:56:15 UTC 2010

I just realized that cdboot does not contain the kernel as boot.flp used 
to, so I guess /boot/kernel has to be there... So it does not seem to 
work with mkisofs. I did

mkisofs -J -R -no-emul-boot -b ./cdboot -iso-level 3 -V FreeBSD_Custom 
-o custom_FreeBSD_8_0_i386_cd.iso custom_FreeBSD_8_0_i386_cd

and it throws:
mkisofs: Uh oh, I cant find the boot image './cdboot'

I tried with the absolute path for cdboot and it does not help either. 
 From the mkisofs man page it says that -no-emul-boot has to be added if 
the size of the image file is not 1200, 1440, or 2880 kB. I noticed that 
the cdboot file is only 1.2 kB, so I guess -no-emul-boot is required... 
Do you have an idea what could be wrong?


Pierre-Luc Drouin wrote:
> Great Thanks! So when I create a boot CD using the boot image, are the 
> kernel files contained in /boot/kernel read at all during boot?
> Manolis Kiagias wrote:
>> On 10/02/2010 11:10 μ.μ., Pierre-Luc Drouin wrote:
>>> Hi,
>>> I would like to create a boot CD using FreeBSD 8.0 but I just noticed
>>> that there is no existing boot.flp file for 8.0. What is the
>>> alternative to get a boot image to create my CD image?
>>> Thanks!
>> You just use the boot/cdboot file from the official CD/DVD, like this
>> (to write to a DVD)
>> growisofs -Z /dev/cd0 -speed 16 -J -R -no-emul-boot -b boot/cdboot
>> -iso-level 3 path-to-your-files
>> or use mkisofs with similar options to write an iso image, i.e.
>> mkisofs -J -R -no-emul-boot -b boot/cdboot -iso-level 3 -o
>> /path/to/your.iso path-to-your-files

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